Generally, a 3-dimensional (3D) image (or stereoscopic image) is based upon the principle of stereoscopic vision of both human eyes. A parallax between both eyes, in other words, a binocular parallax caused by the two eyes of an individual being spaced apart at a distance of approximately 65 millimeters (mm) is viewed as the main factor that enables the individual to view objects 3-dimensionally. When each of the left eye and the right eye respectively views a 2-dimensional (or flat) image, the brain combines the pair of differently viewed images, thereby realizing the depth and actual form of the original 3D image.
Such 3D image display may be broadly divided into a stereoscopic method, a volumetric method, and a holographic method. For example, a 3D image display device adopting the stereoscopic method corresponds to an image display device that adds depth information to 2D images and that uses such depth information to enable the viewer to experience the dynamic, live, and realistic perception of the 3D image.
Furthermore, the method of displaying 3D images may be broadly divided into a method of wearing special glasses and a method of not wearing any special glasses.